Since the comfort of passengers and the saving of space are constant preoccupations of the manufacturers of vehicles, especially motor vehicles, there are many types of seats of which the back can be folded down onto the sitting surface, and it is increasingly desirable that there should also be the possibility of adjusting the inclination of this back during use, in order to ensure that the user is truly comfortable.
However, it can be seen that the devices allowing this adjustment of inclination are complex and mostly employ an auxiliary pivoting mechanism which comprises numerous components and which is therefore costly.